An optical network is known that transmits wavelength division multiplexed (WDM) lights including multiple wavebands each consisting of multiplexed optical channels (wavelength channels) of a predetermined bit rate on the order of GHz to THz for each of multiple wavelengths respectively corresponding to multiple optical (wavelength) channels (wavelength channels or light paths) divided based on wavelength by, for example, 100 GHz in a predetermined communication wavelength band, from a predetermined optical node to a plurality of other optical nodes through respective multiple optical fibers in series or in parallel among optical nodes. In such an optical network, an optical path cross-connect apparatus making up each optical node routes optical channels on the basis of wavelengths making up wavelength division multiplexed optical signals transmitted through optical fibers by using the wavelengths as labels to be routed to desired routes (destinations) directly as optical signals through optical paths on the basis of wavelengths, thereby implementing large-capacity transmission with low power consumption.
Because a traffic amount is predicted to increase at an accelerated rate in the optical network due to the recent deployment of ADSL and FTTH and the deployment of services such as high-definition moving image distribution, it is desired to increase the available numbers of wavelength paths and optical fibers and to further increase the scale of optical path cross-connect apparatuses making up nodes in the optical network.